rpmbuild hell

I've been trying to get NetworkManager rebuilt from the src.rpm for OpenSUSE 10.3 because the DHCP timeout is too short for one of the networks I need to connect to (Ubuntu 7.10 can connect fine with a 60 second timeout).

So.

Install source
rpm -ivh NetworkManager-0.6.5-37.4.src.rpm

Build prep
rpmbuild -bp --target=i586 /usr/src/packages/SPECS/NetworkManager.spec

Change #define NM_DHCP_TIMEOUT from 45 to 60
vi /usr/src/packages/BUILD/NetworkManager-0.6.5/src/dhcp-manager/nm-dhcp-manager.c

Build compile
rpmbuild -bc --short-circuit --target=i586 /usr/src/packages/SPECS/NetworkManager.spec

Build install
rpmbuild -bi --short-circuit --target=i586 /usr/src/packages/SPECS/NetworkManager.spec

Now, 'install' complains about not finding NetworkManager.spec in SOURCES (which it wouldn't, because it's in SPECS) and doesn't seem to actually install and rpmbuild -ba or -bb redo the prep stage narking any change made to the source before going through compile and install stages.

So, I can't get it installed through rpmbuild and 'make install' throws up errors I can't be bothered to deal with just yet.

Any ideas?